package org.com.cay.util;

import java.io.InputStream;
import java.sql.*;
import java.util.Properties;

/**
 * JDBC工具类： 1） 获取Connection 2） 释放资源
 */
public class JDBCUtil {

	/**
	 * 获取Connection
	 * 
	 * @return 所获得到的JDBC的Connection
	 */
	public static Connection getConnection() throws Exception {

		/**
		 * 不建议大家把配置硬编码到代码中
		 *
		 * 最佳实践：配置性的建议写到配置文件中
		 */
		// String url = "jdbc:mysql:///spring_data";
		// String user = "root";
		// String password = "root";
		// String driverClass = "com.mysql.jdbc.Driver";

		InputStream inputStream = JDBCUtil.class.getClassLoader().getResourceAsStream("db.properties");
		Properties properties = new Properties();
		properties.load(inputStream);

		String url = properties.getProperty("jdbc.url");
		String user = properties.getProperty("jdbc.user");
		String password = properties.getProperty("jdbc.password");
		String driverClass = properties.getProperty("jdbc.driverClass");

		Class.forName(driverClass);
		Connection connection = DriverManager.getConnection(url, user, password);
		return connection;
	}

	/**
	 * 释放DB相关的资源
	 * 
	 * @param resultSet
	 * @param statement
	 * @param connection
	 */
	public static void release(ResultSet resultSet, Statement statement, Connection connection) {

		if (resultSet != null) {
			try {
				resultSet.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}

		if (statement != null) {
			try {
				statement.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}

		if (connection != null) {
			try {
				connection.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}

	}

}
